<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        let arr=[1,2,3,4,5,3];
        let newItem= arr.find((item,index)=>{
            if(item==3){
                return true
            }
        })

        console.log(newItem);
    </script>
</body>
</html>